Flex support snubber

ABSTRACT

A disc drive is provided with rotatable discs and an actuator assembly having heads adjacent the discs. A flex circuit assembly providing electrical connection between the heads and the disc drive circuitry comprises flex strips routed on the actuator assembly from the heads and a flex affixed on the actuator assembly. A flex support snubber mounted on the side of the actuator assembly has a body portion with a plurality of arms extending therefrom. Each pair of the arms form a groove so that the arms are disposed above and below discs while the discs extend into the grooves. A plurality of slits are interposed between the grooves to support the flex strips therein. An opposite end of the flex support snubber curves to form a U-shaped snubber bend for turning and guiding a dynamic portion of the flex.

RELATED APPLICATIONS

This application is a continuation-in-part of patent application Ser.No. 09/099,044 filed Jun. 17, 1998, U.S. Pat. No. 6,024,019 which claimspriority to Provisional Application Serial No. 60/004,924 filed Oct. 6,1995, and U.S. patent application Ser. No. 60/092,609 filed Jul. 13,1998, which are also hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to the field of disc drive datastorage devices, and more particularly but not by way of limitation, toa flex support snubber for protecting a hard disc drive from damage dueto non-operational, mechanical shocks while retaining and guiding a flexcircuit assembly.

BACKGROUND OF THE INVENTION

Disc drives are commonly used in workstations, personal computers,portables, and other computer systems to store large amounts of data ina form that can be made readily available to a user. In general, a discdrive comprises one or more magnetic discs that are rotated by a spindlemotor at a constant high speed. The surface of each disc is divided intoa series of data tracks which are spaced radially from one anotheracross a band having an inner diameter and an outer diameter. The datatracks extend generally circumferentially around the discs and storedata in the form of magnetic flux transitions within the radial extentof the tracks on the disc surfaces. Typically, each data track isdivided into a number of data sectors that store fixed sized blocks.

A head includes an interactive element such as a magnetic transducerwhich senses the magnetic transitions on a selected data track to readthe data stored on the track, or to transmit an electrical signal thatinduces magnetic transitions on the selected data track to write data tothe track. The head includes a read/write gap that positions the activeelements of the head at a position suitable for interaction with themagnetic transitions on the data tracks of a disc as the disc rotates.

As is known in the art, each head is mounted to a rotary actuator armand is selectively positionable by the actuator arm over a preselecteddata track of the disc to either read data from or write data to thepreselected data track. The head includes a slider assembly having anair bearing surface that causes the head to fly over the data tracks ofthe disc surface due to fluid air currents caused by rotation of thedisc.

Typically, several discs are stacked on top of each other and thesurfaces of the stacked discs are accessed by the heads mounted on acomplementary stack of actuator arms which comprise an actuatorassembly, or “E-block”. The E-block generally includes head wires whichconduct electrical signals from the heads to a flex circuit, which inturn conducts the electrical signals to a flex circuit bracket mountedto a disc drive base deck. For a general discussion of E-block assemblytechniques, see U.S. Pat. No. 5,404,636 entitled METHOD OF ASSEMBLING ADISK DRIVE ACTUATOR, issued Apr. 11, 1995 to Stefanslky et al., assignedto the assignee of the present invention and incorporated herein byreference.

As will be recognized, a continuing trend in the industry is thereduction in size of modern disc drives. As a result, the discs in thedisc stacks of modern disc drives are being brought closer together,providing narrower vertical gaps between adjacent discs. Althoughfacilitating greater amounts of storage capacity, such narrow verticalspacing of the discs gives rise to a problem of increased sensitivity ofthe disc drives to non-operating, mechanical shocks; particularly,predominant failure modes in modern disc drives have been found toinclude damage to the surfaces of the discs and damage to the actuatorarms as a result of mechanical shocks encountered during the shippingand handling of the drives.

Computer modeling of particular disc drives has revealed that oneprimary cause of interference between discs and actuator arms is thefirst mechanical bending mode of the discs, which has been found tocause over 50% of the motion between the arms and discs in selected discdrive designs. The bending mode is generally dependent upon thematerial, diameter and thickness of the discs, and these factors are notreadily modified in a disc drive design.

Thus, there is a need for an improved approach to reducing thesusceptibility of damage in disc drives as a result of non-operating,mechanical shocks.

SUMMARY OF THE INVENTION

The present invention provides a flex support snubber for protecting adisc drive from damage due to non-operational mechanical shocks and forguiding and retaining flex strips of a flex circuit assembly.

As exemplified by preferred embodiments, a disc drive has a disc mountedfor rotation at a constant speed about a vertical axis. The disc has aninner radius and an outer radius. A rotary actuator is mounted adjacentthe disc and is controllably rotatable with respect to the disc. A flexsupport snubber is mounted on the side of the actuator and adjacent thedisc. The flex support snubber has a body portion rigidly affixed to theactuator and includes a plurality of arms extending therefrom and towardthe disc. Each pair of arms form a groove to receive the outer radius ofthe disc.

A plurality of slits are interposed with the grooves to receive flexstrips therein. The slits provide for retention of the flex strips fromthe heads. At an opposite end of the flex support snubber, the flexsupport snubber curves to form a U-shaped bend. The U-shaped bend guidesa dynamic portion of a flex away from the actuator assembly whileproviding stiffness and support for the flex.

Other objects, advantages, and features of the present invention will beapparent from the following description when read in conjunction withthe drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a disc drive in which the present inventionis particularly useful.

FIG. 2 is a cross-sectional, elevational view of the cylindrical-shapedsnubber of FIG. 1.

FIG. 3 is a cross-sectional, elevational view of an L-shaped snubber.

FIG. 4 is a top plan view of a disc drive having a shroud-mountedsnubber.

FIG. 5 is a cross-sectional, elevational view of the shroud-mountedsnubber of FIG. 4.

FIG. 6 is an elevational view of a snubber mounted to an E-block.

FIG. 7 is a top plan view of the E-block and snubber of FIG. 6.

FIG. 8 is an elevational view of an E-block having an over-moldedsnubber.

FIG. 9 is a top plan view of the E-block and snubber of FIG. 8.

FIG. 10 is a cross-sectional, elevational view of a portion of anE-block and an associated pin snubber.

FIG. 11 is a top plan view of the E-block and pin snubber of FIG. 10.

FIG. 12 is an elevational view of a portion of an E-block with a flexcircuit assembly having flex extensions which serve as a disc snubber.

FIG. 13 is an elevational view of a portion of an E-block with a flexcircuit assembly having flex strips adjacent actuator arms and tabswhich serve as a disc snubber.

FIG. 14 is an isometric view of a portion of an E-block with a flexcircuit assembly having flex strips adjacent the actuator arms supportedwithin a flex support snubber.

FIG. 15 is an isometric view of the flex support snubber of FIG. 14.

FIG. 16A is an elevational front view of an alternative embodiment of aflex support snubber;

FIG. 16B is an elevational back view thereof.

DETAILED DESCRIPTION

Turning now to the drawings and more particularly to FIG. 1, showntherein is a top plan view of a disc drive 10 to which the presentinvention is particularly useful. The disc drive 10 includes a base deck12 to which various disc drive components are mounted and a top cover14, which provides a sealed internal environment for the disc drive 10.The top cover 14 is shown in a partial cut-away fashion to exposeselected components of interest.

Mounted to the base deck 12 is a spindle motor (shown generally at 16)to which a plurality of discs 18 are mounted for rotation at a constanthigh speed. Adjacent the discs 18 is an actuator assembly 20(hereinafter sometimes also referred to as an “E-block”) which pivotsabout a pivot shaft 22 in a rotary fashion. The E-block 20 includesactuator arms 24 which support gimbal assemblies 26 (hereinafter alsosometimes referred to as “load springs”). The load springs 26 in turnsupport heads 28, with each of the heads 28 corresponding to a surfaceof one of the discs 18. As provided hereinabove, the heads 28 arepositionably located over data tracks (not shown) of the discs 18 inorder to read data from and write data to the tracks, respectively. Atsuch time that the disc drive 10 is not in use, the heads 28 are movedto landing zones (denoted at broken line 30), which are located in FIG.1 near the inner diameter of the discs 18.

It will be recognized that the E-block 20 is provided with a latchingarrangement (shown generally at 32) to secure the E-block 20 when thedisc drive 10 is not in use. For a general discussion of typical E-blocklatching arrangements, see U.S. Pat. No. 5,231,556 entitled SELF-HOLDINGLATCH ASSEMBLY, issued Jul. 27, 1993 to Blanks, assigned to the assigneeof the present invention and incorporated herein by reference.

Continuing with FIG. 1, the E-block 20 is controllably positioned by wayof a voice coil motor (VCM, shown generally at 34), comprising anactuator coil 36, immersed in the magnetic field generated by apermanent magnet 38. It will be recognized that a magnetically permeableflux path (such as a steel plate) is mounted above the actuator coil 36to complete the magnetic circuit of the VCM 34, but for purposes ofillustration this flux path has not been shown in FIG. 1. Whencontrolled DC current is passed through the actuator coil 36, anelectromagnetic field is set up which interacts with the magneticcircuit of the VCM 34 to cause the actuator coil 36 to move relative tothe permanent magnet 38 in accordance with the well-known Lorentzrelationship. As the actuator coil 36 moves, the E-block 20 pivots aboutthe pivot shaft 22. causing the heads 28 to move across the surfaces ofthe discs 18.

To provide the requisite electrical conduction paths between the heads28 and disc drive read/write circuitry (not shown), head wires (notseparately shown) are routed on the E-block 20 from the heads 28, alongthe gimbal assemblies 26 and the actuator arms 24, to a flex circuitassembly 40. The head wires are secured (by way of a suitable solderingprocess) to corresponding pads (not separately designated in FIG. 1) ofa printed circuit board (PCB) 42 of the flex circuit assembly 40. Inturn, the flex circuit assembly 40 is connected to a flex circuitbracket (shown generally at 44) in a conventional manner. Preferably,the head wires are conductive wires having a relatively small diameterand are coated with a thin insulating layer (such as teflon). Forpurposes of clarity, this thin insulating layer is not separatelydesignated in the drawings; however, it will recognized that thisinsulating layer is not present at the ends of the head wires where thehead wires are soldered to the pads of the PCB 42. It will further berecognized that the actuator arms 24 and the gimbal assemblies 26 areprovided with suitable wire guides (not separately shown) to capture andretain the head wires.

Additionally, FIG. 1 shows a snubber 100, which comprises acylindrically-shaped assembly adjacent the stack of discs 18. As will bediscussed in more detail below, the snubber 100 protects the disc drive10 from damage as a result of mechanical shocks provided to the discdrive 10 without otherwise interfering with the normal operation of thedrive. Particularly, the snubber 100 is provided with a configurationsuch that; when significant deflection of the discs 18 is induced by amechanical shock incident, the discs 18 will contact the snubber 100instead of the E-block 20, thus minimizing damage to the E-block 20 andthe discs 18.

Referring now to FIG. 2, shown therein is a cross-sectional, elevationalview of the snubber 100, in conjunction with outlying portions of thediscs 18 and the base deck 12 of FIG. 1. More particularly, FIG. 2 showsthe snubber 100 to comprise a body portion having a plurality of snubberarms 102 which extend radially away from the center or central axis ofthe snubber 100 and, as shown in FIG. 2, substantially symmetrical aboutthe central axis of the snubber 100. The snubber 100 is secured to thebase deck 12 by way of a suitable fastener 104, which as shown in FIG. 2is provided with a threaded portion 106 which engages with a threadedhole 108 of the base deck 12.

The snubber arms 102 are configured to extend nominal distance withinthe radial extent of the discs 18, as shown. Particularly, the snubberarms 102 are configured to extend sufficiently into the stack of discs18 to constrain vertical deflection of the discs 18 as a result ofmechanical shock. However, the snubber arms 102 preferably do not extendto the recording surfaces (not shown) of the discs 18, as damage to thesurfaces of the discs 18 may occur at locations where the discs 18contact the snubber arms 102 during deflection of the discs 18. Thus,the distance the snubber arms 102 extend into the stack of discs 18 isan important consideration and will be dependent upon the design of aparticular disc drive.

Additionally, the snubber arms 102 are vertically dimensioned to fitbetween the discs 18 as shown. It is expressly contemplated that thevertical dimensions of the snubber arms 102 will be less than thevertical dimensions of the gaps between adjacent discs 18, but will begreater than the vertical dimensions of the actuator arms 24 (of FIG.1), to prevent contact between the discs 18 and the actuator arms 24during deflection of the discs 18.

The snubber 100 is constructed from a suitable material which willprovide the desired mechanical strength to constrain deflection of thediscs 18, while at the same time will minimize the potential for damageto the snubber 100 and to the discs 18. Preferably, the snubber 100 isconstructed from a plastic, non-marring material, such as polycarbonateor acetal. As shown in FIG. 1, the snubber 100 is preferably mountednear the E-block 20, in order to maximize protection of the actuatorarms 24 and the discs 18. It will be recognized, however, that thesnubber 100 can be located at positions other than adjacent to theE-block 20, as desired, further, the use of multiple snubbers 100 atvarious positions about the circumference of the discs 18 could be foundto be advantageous in particular disc drive designs. Additionally, it iscontemplated that the snubber arms 102 could extend only about a portionof the circumference of the snubber 100, the portion being adjacent thediscs 18.

Referring now to FIG. 3, shown therein is a cross-sectional, elevationalview of a generally L-shaped snubber (designated as 100A) having aconfiguration similar to that of the cylindrical snubber 100 of FIGS. 1and 2. As with the snubber 100, the snubber 100A of FIG. 3 includessnubber arms 102A which extend radially between adjacent discs 18.Additionally, the snubber 100A is secured to the base deck 12 with asuitable fastener 104A by way of a threaded portion 106A and acorresponding threaded hole 108A in the base deck 12. However, thesnubber 100A has an L-shaped, cross-sectional configuration, as shown,including a vertical portion 110A and a horizontal portion 112A, whichare configured as desired to provide the necessary strength for thesnubber 100A, as well as to conform to internal space requirements ofthe disc drive 10. It will be recognized that the snubber 100A of FIG. 3will generally require less space and comprise less material than thesnubber 100, which may be important considerations in small form factoror low cost drive designs.

Referring now to FIG. 4, shown therein is a disc drive 10A, which has aconfiguration similar to the disc drive 10 of FIG. 1 (for purposes ofclarity, the same reference numbers for components shown in FIG. 1 havebeen used in FIG. 4). However, the disc drive 10A includes a disc shroud46, which comprises a vertically extending flange adjacent the discs 18.As will be recognized, the disc shroud 46 is typically used to reducewind resistance from the spinning discs 18 in order to reduce powerrequirements of the disc drive 10A, an important consideration in lowpower disc drive applications. Typically, the disc shroud 46 is formedas part of the base deck 12 and extends upwardly therefrom.

Additionally, FIG. 4 shows a snubber (designated as 100B) which ismounted to the disc shroud 46 and to the base deck 12. It will berecognized that the E-block 20 shown in FIG. 4 is at a differentrotational position than the E-block 20 shown in FIG. 1 to more fullyillustrate the snubber 100B; however, it will be recognized that aportion of the snubber 100B will extend under the E-block 20 when theE-block 20 is positioned as shown in FIG. 1. As with the snubbers 100,100A discussed hereinabove, the snubber 100B serves to protect the discdrive 10 from damage due to deflection of the discs 18 as a result ofmechanical shock.

The snubber 100B is shown in greater detail in FIG. 5, which provides across-sectional, elevational view of the snubber 100B in conjunctionwith the disc shroud 46, the discs 18 and the base deck 12.Particularly, FIG. 5 shows the snubber 100B to include snubber arms102B, which extend radially between adjacent discs 18 in a mannersimilar to that described hereinabove As shown in FIGS. 4 and 5, thesnubber 100B is provided with a vertically oriented, C-shapedconfiguration so that the snubber 100B wraps around the end of the discshroud 46, as shown, and is secured to the disc shroud 46 by way of asuitable threaded fastener 114. Additionally, the snubber 100B issecured to the base deck 12 by way of a suitable base deck fastener 104B(by way of threads 106B which engage with a threaded hole 108B in thebase deck 12). Thus, the fasteners 104B and 114 secure the snubber 100Brelative to the base deck 12 and the disc shroud 46. The vertical heightof the fastener 104B and a horizontal portion 116 of the snubber 100Bare provided such that mechanical clearance exists between the fastener104B and the horizontal portion 116 and the E-block 20 (as shown in FIG.4).

Referring now to FIG. 6, shown therein is an elevational view of anE-block 20A, which is generally similar to the E-block 20 discussedhereinabove, except to the extent that the E-block 20A includes anE-block mounted snubber 100C mounted to the “up-wind” side of theE-block 20. The E-block 20A is shown in conjunction with the discs 18,including the extension of the actuator arms 24 between adjacent discs18. For purposes of clarity, the load springs 26 and heads 28 have notbeen shown in FIG. 6, but it will be understood that these elementsextend radially from the actuator arms 24; particularly, it will bereadily understood by those skilled in the art that the top and bottomactuator arms 24 have one load spring 26 and head 28 extendingtherefrom, respectively, and the rest of the actuator arms 24 have twoload springs 26 and heads 28 extending therefrom, respectively.

The snubber 100C is shown mounted to the side of the E-block 20A, withsnubber arms 102C extending adjacent to the corresponding actuator arms24 between adjacent discs 18. The snubber arms 102C operate in a manneras described hereinabove to protect the actuator arms 24 from damage asa result of deflection of the discs 18, by limiting the vertical extentof travel of the outer diameters of the discs 18. It will be understoodthat the snubber 100C is mounted to the side of the E-block 20A by wayof a suitable fastener 118, which preferably inserts through a hole (notshown) in the snubber 100C and engages with a corresponding threadedhole (also not shown) in the E-block 20A. It will be recognized by thoseskilled in the art that in actuator designs that use a screw to securethe bearing cartridge (not separately designated, but surrounding thepivot shaft 22 shown in FIG. 7), this screw can also serve as thefastener 118 shown in FIG. 6 to secure the snubber 100C to the E-block20A.

An important advantage of the snubber 100C is that the protectionprovided by the snubber arms 102C is generally maximized by the adjacentplacement of the snubber arms 102C to the actuator arms 24. Although notshown in the drawings, it will be recognized that the configuration ofthe scrubber arms 102C can be modified as desired to account for therotary movement of the E-block 20A relative to the discs 18 to minimizethe radial extent of the snubber arms 102C into the stack of discs 18over the range of movement of the E-block 20A.

Referring now to FIG. 7, shown therein is a top plan view of the E-block20A and snubber 100C of FIG. 6. For reference, FIG. 7 shows the E-block20A to be pivotable about the pivot shaft 22, as provided above;additionally, the latching arrangement 32 and the flex circuit assembly40 of FIGS. 1 and 4 are also shown in FIG. 7, for purposes of clarity.

As shown in FIG. 7, the snubber 100C of FIG. 6 is mounted to the side ofthe E-block 20A by way the fastener 118. Further, the snubber arms 102Cextend as shown along the actuator arms 24.

Referring now to FIG. 8, shown therein is an elevational view of anE-block 20B, similar in configuration and operation to the E-blocks 20and 20A discussed hereinabove. The E-block 20B is also shown inconjunction with the discs 18 and includes the actuator arms 24extending radially between the discs 18, in a manner similar to theE-block 20A of FIG. 6.

However, the E-block 20B of FIG. 8 includes the use of an over-moldedsnubber 100D, formed using a suitable over-molding process wherein anassembled stack of actuator arms 24 is selectively coated with a layerof material, such as plastic. Particularly, it is contemplated that theE-block 20B of FIG. 8 is subjected to such a process in order to formthe over-molded snubber 100D thereon. Particularly, the snubber 100D issimilar in configuration to the snubber 100C of FIG. 6, so that snubberarms 102D extend radially between the discs 18 and adjacent to theactuator arms 24; however, instead of providing the snubber arms 102Djust adjacent the sides of the actuator arms 24, the over-molded snubber100D of FIG. 8 includes material along the top and bottom surfaces ofthe actuator arms 24 as well. Additionally, the over-molding processallows the material comprising the snubber arms 102D to be “curved” withrespect to the actuator arms 24, in order to maintain minimum extensionof the snubber arms 102D into the stack of discs 18 as the E-block 20Brotates with respect to the discs 18.

The curved characteristic of the snubber arms 102D is more fullyillustrated in FIG. 9, which shows a top plan view of the E-block 20B ofFIG. 8. It will be recognized that the curved characteristic of thesnubber arms 102D of FIG. 9 facilitates nominally constant extension ofthe snubber arms 102D into the stack of discs 18, irrespective of therotary position of the E-block 20B. Further, it will be recognized that,depending upon the rotary position of the E-block 20B with respect tothe discs 18 (not shown in FIG. 9), different portions of the snubberarms 102D will extend into the stack of discs 18. Of course, the curvedcharacteristic of the snubber arms 102D can be selected as desired,depending upon the design of a particular drive, including the relativeposition of the pivot shaft 22 with respect to the discs 18 (and theresulting range of motion of the E-block 20B and the discs 18).

Referring now to FIG. 10, shown therein is a cross-sectional elevationalview of a portion of an E-block 20C, which is generally similar to theE-blocks (20, 20A and 20B) described hereinabove, but includes a pinsnubber 100E, comprising a plurality of pins 122 extending through eachof a plurality of corresponding actuator arms 24A. The actuator arms 24Aare generally similar in all respects to the actuator arms 24 describedhereinabove, except that the actuator arms 24A are additionally providedwith holes 124, through which the pins 122 are inserted duringfabrication of the E-block 20C. As shown in FIG. 10, the pins 122 aresized and located accordingly with respect to the outer extreme of thediscs 18, so that the pins 122 operate in a fashion as generallydescribed above to limit deflection of the discs 18 as a result ofmechanical shocks to the assembly shown therein. The pins 122 areselected from a suitable material that will maximize protection to theE-block 20C and at the same time minimize damage to the discs 18 in theevent of a mechanical shock sufficient to bring the outer extremes ofthe discs 18 into contact with the pins 122. In one preferred method offabrication, the holes 124 are drilled through the actuator arms 24Aduring a single operation, a single pin (not shown) in pressed throughall of the holes 124 and the single pin is subsequently machined intothe pins 122 configured as shown in FIG. 10.

A top plan view of the E-block 20C of FIG. is shown in FIG. 11,illustrating the relative placement of the pins 122 and the actuatorarms 24A. Although the pins 122 have been shown in FIG. 11 to generallyhave the shape shown, other shapes may be selected as desired, includingshapes having a curved characteristic similar to the snubber arms 102Dof FIG. 9 to maintain the radial extent of the pins 122 into the stackof discs 18 (not shown in FIG. 11).

Referring now to FIG. 12, shown therein is an elevational view of aportion of an E-block 20D adjacent the stack of discs 18, the E-block20D including a flex circuit assembly 40A which is generally similar tothe flex circuit assembly 40 described hereinabove, with the addition offlex extensions 132 which extend from the flex circuit assembly 40 intothe stack of discs 18. More particularly, the flex extensions 132 extendfrom a PCB 42A of the flex circuit assembly 40A, as shown.

As described hereinabove, electrical signals are transmitted by way ofhead wires (designated collectively as 134 in FIG. 12) which are routedfrom the heads 28 (not shown in FIG. 12) and along the actuator arms 24to the PCB 42A. The distal ends of the head wires 134 are soldered tocorresponding pads (collectively “136”) on the PCB 42A as shown. The PCB42A is rigidly mounted to the side of the E-block 20D. The flexextensions 132 extend radially between the discs 18, and aresufficiently rigid to limit deflection of the discs 18, in a mannersimilar to that described hereinabove. It will be recognized that theadvantages associated with the flex circuit assembly 40A of FIG. 12include the benefit that the snubber features of the flex circuitassembly 40A can be readily incorporated into the design of the flexcircuit assembly 40A. Thus, the flex circuit assembly 40A can beimplemented into existing drive designs without the need for E-block oradditional assembly steps.

Referring now to FIG. 13, shown therein is an elevational view of aportion of an E-block 20E having a flex circuit assembly 40B, which issimilar to the flex circuit assembly 40A of FIG. 12, with the exceptionthat the flex circuit assembly 40B includes flex strips 142 which extendalong corresponding actuator arms 24B.

The flex strips 142 accommodate connection paths (not shown) from a PCB(not shown) to the heads 28 (not shown in FIG. 13) and serve asalternatives to the head wires 134 of FIG. 12. It will be recognizedthat the actuator arms 24B include conventional features (notparticularly shown) to accommodate the flex strips 142 and such featuresare generally different from features used to capture and retain thehead wires 134 (shown in FIG. 12).

The flex strips 142 of FIG. 13 include tabs 144, which are located nearthe outer extent of the discs 18. The tabs 144 extend vertically fromthe flex strips 142 and are configured to limit the deflection of thedisc 18, in the manner described hereinabove. As with the flex circuitassembly 40A of FIG. 12, the flex circuit assembly 40B of FIG. 13 can bereadily incorporated into existing drive designs that use conventionalflex strips instead of wires.

Turning now to FIG. 14, shown therein is an isometric view of a portionof an E-block 20F upon which a flex circuit assembly can be attached. Asdiscussed above, the flex circuit assembly 40 (FIG. 1), provides therequisite electrical connection paths for the E-block 20F whilefacilitating pivotal movement of the E-block 20F during operation. Theflex circuit assembly 40 includes a printed circuit board 42 (partiallyshown) to which flex strips 142 (also sometimes referred to asflex-on-suspension (FOS)) are connected as shown for the embodiment ofFIG. 13. The flex strips 142 are routed along the actuator arms 24 andthe flexures 26 (FIG. 1) to the heads 28. The flex circuit assemblyfurther includes a flex 150 not included in FIG. 14, but shownin-therein (FIG. 1) to which the printed circuit board 42 is affixed.The flex 150 mechanically terminates at the flex circuit bracket 44(FIG. 1) and electrically terminates at a termination bracket (notshown). The flex 150 comprises a plastic ribbon having encapsulatedsignal paths.

Of particular interest in FIG. 14 is a flex support snubber 152constructed in accordance with a preferred embodiment of the presentinvention. The flex support snubber 152 is made from a plastic,injection molded material and is mounted to the side of the E-block 20F.In particular, the flex support snubber 152 contacts the side of theE-block 20F proximate to the flex circuit assembly 40 (FIG. 1). Itshould be understood that the flex support snubber 152 is mounted to theE-block 20F by any suitable method.

Turning now to FIG. 15, shown therein is an isometric view of the flexsupport snubber 152. The flex support snubber 152 has a body portion 154with a plurality of arms 156 extending therefrom at a distal end of theflex support snubber 152. Each pair of the arms 156 form a groove 158 sothat the arms 156 are disposed above and below discs 18 (FIG. 14). Thegrooves 158 receive the outer diameters of the discs 18 to accommodateplacement of the flex support snubber 152 without contacting the discs18 in the absence of a mechanical shock. It should be noted that variousshapes and sizes of the arms 156 and grooves 158 are within the scope ofthe present invention in performing the snubbing function.

A plurality of slits 160 are formed in the body portion 154 and areinterposed between the grooves 158. The slits 160 extend adjacent theactuator arms 24 for a distance sufficient to provide support for theflex strips 142. At an opposite end of the flex support snubber 152, theflex support snubber 152 curves to form a U-shaped snubber bend 162.

Returning to FIG. 14, the arms 156 extend adjacent the actuator arms 24to prevent contact between the discs 18 and the actuator arms 24 whenapplication of a non-operational shock results in deflection of thediscs 18. Moreover, the arms 156 reduce the effects of non-operationalshock by limiting deflection of the actuator arms 24 to prevent headslap. As the disc drive 10 assumes its operational mode, the actuatorarms 24 are brought over the disc outer diameters and the flex supportsnubber 152 is rotated outside the disc outer diameters. Thus, theplacement of the flex support snubber 152 on the E-block 20F preventscontact of the discs 18 with the flex support snubber 152 duringoperation.

The slits 160 that are interposed between grooves 158 extend adjacentthe actuator arms 24 to receive the flex strips 142 (not shown) that areoperably coupled to the E-block 20F. As noted above, the flex strips 142are routed from the heads 28 (not shown) to a PCB (partially shown). Theflex strips 142 are guided into the slits 160 so that the flex strips142 are folded and retained in place within the slits 160. The flexstrips 142 folded through the slits 160 are attached to the body portion154 in a suitable manner such as through hot-bar soldering. Thus, theflex support snubber 152 effectively retains the flex strips 142. Itshould be understood that the present invention is equally applicable inretaining flex wires as opposed to flex strips 148.

The U-shaped snubber bend 162 of the flex support snubber 152, as shownin FIG. 14, acts to position and guide a dynamic portion 163 (FIG. 1) ofthe flex 150 of the flex circuit assembly 40B. The dynamic portion 163comprises the portion of the flex 150 supported between the printedcircuit board 42 and the flex circuit bracket 44. Proper positioning ofthe dynamic portion 163 of the flex 150 is required to prevent the flex150 from rubbing the base deck 12, top cover 14, or the discs 18 as theE-block 20F pivots about the pivot shaft 22.

The U-shaped snubber bend 162 therefore replaces a traditional secondarystiffener to turn and guide the flex 150 away from the E-block 20F andtoward the flex circuit bracket 44. The spring force of the folded flex150 pushes against the inside of the U-shaped snubber bend 162 toeffectively retain the flex 150 therein while the body portion 154operates as a flex stiffener to support the flex 150. The flex supportsnubber 152 eliminates the need for multiple parts in guiding andretaining the flex 150, and thereby improves the balance of the E-block20F.

In sum, the flex support snubber 152 of the present invention providesease of manufacture by eliminating the need for multiple parts for discsnubbing, retaining the flex strips 142 and turning and positioning theflex strips 142 to guide the dynamic region 163 away from the E-block20F, base deck 12, and top cover 14.

Moreover, the mass of the E-block 20F is effectively reduced byreplacing multiple parts with the flex support snubber 152.

Turning now to FIGS. 16A and 16B, shown therein are elevational views ofan alternative embodiment of a flex support snubber 170. The flexsupport snubber 170 is made from a plastic, injection molded materialand is mounted to the side of the E-block 20F (FIG. 14). In particular,the flex support snubber 170 contacts the side of the E-block 20Fproximate to the flex circuit assembly 40 (FIG. 1). It is understoodthat the flex support snubber 170 is mounted to the E-block 20F by anysuitable method such as with screws inserted through apertures in theflex support snubber 170.

The flex support snubber 170 has a body portion 172 with a plurality ofarms 174 extending therefrom at a distal end of the flex support snubber170. Each pair of the arms 174 form a groove 176 so that the arms 174are disposed above and below discs 18 (FIG. 1). Secondary grooves 178extend from grooves 176 and are disposed within the body portion 172. Aplurality of slits 180 extend into the body portion 172 and areinterposed between the grooves 176. The slits 180 extend adjacent theactuator arms 24 for a distance sufficient to provide support for theflex strips 142. The body portion 172 further comprises a wedge portion182 to provide for a snug fit against the side of the E-block 20F.

Continuing with FIG. 16, the arms 174 extend adjacent the actuator arms24 to prevent contact between discs 18 (FIG. 1) and actuator arms 24when application of a non-operational shock results in deflection of thediscs 18. Moreover, the arms 174 reduce the effects of non-operationalshock by limiting deflection of the actuator arms 24 to prevent headslap. When the disc drive 10 is operational, the actuator arms 24 arebrought over the disc outer diameters and the flex support snubber 170is rotated outside the disc outer diameters, thereby preventing contactof the discs 18 with the flex support snubber 170 during operation.

The slits 180 interposed between the grooves 176 extend adjacent to theactuator arms 24 to receive the flex strips 142 (not shown) that areoperably coupled to the E-block 20F. As noted above, the flex strips 142are routed from the heads 28 to the flex circuit assembly 40 (FIG. 1).The flex strips 142 are guided into the slits 180 so that the flexstrips 142 are folded and retained in place within the slits 180. Theflex strips 142 folded through the slits 180 are attached to the bodyportion 172 in a suitable manner such as through hot-bar soldering.Thus, the flex support snubber 170 effectively retains the flex strips142 while the body portion 172 operates as a flex stiffener to supportthe relatively flexible flex strips 142. It is understood that thepresent invention is equally applicable in retaining flex wires asopposed to flex strips 142.

In view of the foregoing, it will be recognized that the presentinvention is directed to an apparatus for providing disc snubbing andflex support and guidance in a disc drive. In accordance with preferredembodiments, a disc drive 10 is provided with a rotatable disc 18comprising a recording surface and an actuator assembly 20 adjacent thedisc 18. The actuator assembly comprises gimbal assemblies 26 which inturn support heads 28. A flex circuit assembly 40 provides the requisiteelectrical connection between the heads and the disc drive circuitry. Aflex circuit assembly 40 includes flex strips 142 routed on the actuatorassembly from the heads and a flex 150 affixed on the actuator assembly.

A flex support snubber 152 mounted on the side of the actuator assemblyhas a body portion 154 with a plurality of arms 156 extending therefrom.Each pair of the arms form a groove 158 so that the arms are disposedabove and below the discs. The grooves between the arms receive theouter diameters of the discs to accommodate placement of the flexsupport snubber without contacting the discs in the absence of amechanical shock. A plurality of slits 160 are interposed between thegrooves to support the flex strips therein. An opposite end of the flexsupport snubber curves to form a U-shaped snubber bend 162 for turningand guiding a dynamic portion 163 of the flex of the flex circuitassembly.

It will be clear that the present invention is well adapted to carry outthe objects and attain the ends and advantages mentioned as well asthose inherent therein. While presently preferred embodiments have beendescribed for purposes of this disclosure, numerous changes may be madewhich readily suggest themselves to those skilled in the art and whichare encompassed in the spirit of the invention disclosed and as deemedin the appended claims.

What is claimed:
 1. A disc drive comprising: a base deck; a spindlemotor mounted to the base deck; a disc mounted to the spindle motor forrotation about a vertical axis, the disc having an inner radius and anouter radius; an actuator assembly mounted to the base deck adjacent thedisc and controllably rotatable with respect to the disc; a flex circuitassembly operably coupled to the actuator assembly, the flex circuitassembly having a flex and at least one flex strip extending along theactuator assembly; and a flex support snubber adjacent the disc,comprising: a body portion rigidly affixed to the actuator assembly andsupporting the flex circuit assembly; a plurality of arms extending fromthe body portion toward the disc outer radius and disposed above andbelow the disc, each arm having a distal end at a position adjacent thedisc between the inner and outer radii of the disc toward the outerradius of the disc, wherein the arms limit deflection of the disc at theouter radius of the disc as a result of a mechanical shock force appliedto the disc drive to minimize damage to the disc drive and the bodyportion defining a plurality of slits interposed between adjacent arms,the plurality of slits receiving and supporting the flex strips on theactuator assembly.
 2. The disc drive of claim 1 wherein the plurality ofslits extend within the body portion adjacent the actuator arms for adistance sufficient to provide support for the flex strips.
 3. A discdrive comprising: a base deck; a spindle motor mounted to the base deck;a disc mounted to the spindle motor for rotation about a vertical axis,the disc having an inner radius and an outer radius; an actuatorassembly mounted to the base deck adjacent the disc and controllablyrotatable with respect to the disc; a flex circuit assembly operablycoupled to the actuator assembly, the flex circuit assembly having aflex with a dynamic portion and at least one flex strip extending alongthe actuator assembly; and a flex support snubber adjacent the disc,comprising: a body portion rigidly affixed to the actuator assembly andsupporting the flex circuit assembly; a plurality of arms extending fromthe body portion toward the disc outer radius and disposed above andbelow the disc, each arm having a distal end at a position adjacent thedisc between the inner and outer radii of the disc and toward the outerradius of the disc, wherein the arms limit deflection of the disc at theouter radius of the disc as a result of a mechanical shock force appliedto the disc drive to minimize the damage to the disc drive; and a firstend and a second end of the body portion, wherein the first end havingsnubber arms and the second end curving to form a U-shaped snubber bend,the U-shaped snubber bend providing support for the flex while turningand positioning the dynamic portion away from the actuator assembly toprevent undesired contact between the dynamic portion and the actuatorassembly.
 4. A flex support snubber for protecting a disc from contactwith an actuator assembly in a disc drive and for retaining flex stripsand positioning a flex of a flex circuit assembly, the disc having aninner radius and an outer radius, the flex support snubber comprising: abody portion rigidly affixed to the actuator assembly and supporting theflex circuit assembly; a plurality of arms extending from the bodyportion toward the disc outer radius and disposed above and below thedisc, each arm having a distal end located at a position adjacent thedisc between the inner and outer radii of the disc and toward the outerradius of the disc, wherein the arms limit deflection of the disc at theouter radius of the disc as a result of mechanical shock force appliedto the disc drive to minimize damage to the disc drive; and the bodyportion defining a plurality of slits interposed between adjacent arms,the plurality of slits receiving and supporting the flex strips on theactuator assembly.
 5. The disc drive of claim 4 wherein the plurality ofslits extend within the body portion adjacent the actuator arms for adistance sufficient to provide support for the flex strips.
 6. A flexsupport snubber for protecting a disc from contact with an actuatorassembly in a disc drive and for retaining flex strips and positioning aflex with a dynamic portion of a flex circuit assembly, the disc havingan inner radius and an outer radius, the flex support snubbercomprising: a body portion rigidly affixed to the actuator assembly andsupporting the flex circuit assembly; a plurality of arms extending fromthe body portion toward the disc outer radius and disposed above andbelow the disc, each arm having a distal end located at a positionadjacent the disc between the inner and outer radii of the disc andtoward the outer radius of the disc, wherein the arms limit deflectionof the disc at the outer radius of the disc as a result of a mechanicalshock force applied to the disc drive to minimize damage to the discdrive; and a first end and a second end of the body portion, wherein thefirst end having snubber arms and the second end curving to form aU-shaped snubber bend, the U-shaped snubber bend providing support forthe flex while turning and positioning the dynamic portion away from theactuator assembly to prevent undesired contact between the dynamicportion and the actuator assembly.